Answer this question truthfully
### Question: What causes Chronic cystic mastitis ?
### Response: The exact cause is not known. It is believed that hormones made in the ovaries can make a woman's breasts feel swollen, lumpy, or painful before or during menstruation each month.
Up to half of women have this problem at some time during their life. It is most common between the ages of 20 and 45. It is rare in women after menopause, unless they are taking estrogen.
Some women feel that eating chocolate, drinking caffeine, or eating high-fat foods cause their symptoms. But there is no clear proof of this.